Alan Duncan remembers ­crying when he watched the suffering of orphan children in Kurdistan on television.

As their families were ­murdered and thrown into mass graves by ISIS, he watched the horror unfold through news bulletins and – like everyone else – felt ­helpless. But Alan didn’t do the same as everyone else. He didn’t dry his eyes and get on with his day. He decided to fight back.

As a Royal Irish Regiment veteran, who served in the first Gulf War as well as enduring seven years of the troubles in Northern Ireland, he knew he could help.

So he spoke to Karen, his partner of 14 years, and told her he would be ­leaving for Iraq in November 2014.

Alan – who was 48 years old and had left the Army 13 years earlier – says she was less than thrilled about his decision, but adds: “She understood how I felt. I couldn’t sit back and do nothing.”

Militants of the Islamic State of Iraq (Image: Getty)

Eighteen months on from that difficult conversation, Alan has fought on the front line alongside the Peshmerga, the military forces of the autonomous region of Iraqi Kurdistan. Together, they are slowly regaining control of the key areas of the country lost in the initial battles to ISIS, also known as Islamic State and Daesh . And, in the wake of last week’s terror attacks in Belgium, he is clear that here in Europe we should ­remember the day-to-day ­horrors of the volatile region.

“Brussels was a tragedy,” he says. “But people need to know that tragedy is repeated here every day. Peshmerga are dying fighting Daesh to save us as well as their own people.”

Alan Duncan (Image: Jane Barlow)

Alan sleeps in trenches with other troops, eats rice and soup and communicates with the little Kurdish he knows.

He flies back to the north east of Scotland to see Karen when he can but rarely gets to call home – he says having a video chat with her from the front line would terrify her.

Alan is an unpaid volunteer and has come under heavy fire, but his main task is training female snipers.

“These women are incredibly tough,” he says. “I have to prove myself to them every day to ensure their respect. When they hit a target, they look at me as if to say, ‘I’m as good as you’. Then I’ll hit the same ­target kneeling down without a rifle rest. When they can do that, my work with them will be done.

An Iraqi Kurdish Peshmerga fighter (Image: Getty)

“A sniper has to be prepared to get an ­individual in their sights and fire, knowing they are going to kill him. It’s more personal than firing from the front line, never knowing whether you’ve found the ­target. But the women have every motivation you can imagine. All of them have lost loved ones to Daesh .”

Most of the women are in their early 20s – one is ­married and has a six-year-old child. To train, they had to overcome Muslim ­cultural issues.

Alan says: “At first it was hard for them to lay down in front of me, a man. But they quickly realised they could not do the job without ­getting past that and they wanted to do the job.”

Iraqi Yezidi women are seen during a military training (Image: Getty)

He has seen friends and ­comrades killed or horribly injured. But the worst horrors he has encountered have been in refugee camps.

“I was ­escorting aid workers to the camps and they were ­interviewing a Yazidi woman who had escaped from Daesh ,” he says. “A group of armed men had burst into her home when she was captured. She had a four-year-old son who was taken outside while they raped her. Later they brought her food and water. They made her eat and after a few mouthfuls they asked her how her son tasted.

“That’s what the Peshmerga are fighting. They’re trying to rid the world of the cancer that is Daesh . Muslims are laying down their lives to fight, ­alongside Christians and Yazidis, against a Muslim ­aggressor. More Muslims have died fighting Daesh than any other group.” It’s not just land they are fighting for. Alan says the battle against ISIS is vital to stop terror attacks in Europe.

Female snipers being trained in Iraq

“Yet we leave it up to this ill-equipped army of locals, reliant on weapons from the 1960s or worse, to rid the world of one of the greatest threats we’ve ever known,” he says. “I’m ashamed we have done so little when so much is at stake for the world.”

That’s why he has made the sacrifice to fight with the Peshmerga, using his military skills to fight for a cause he believes in. “I love Karen, I love my ­family and I loved my life with them,” he adds.

Displaced people from the minority Yazidi sect (Image: Reuters)

“But I’ve told them I won’t stop until Daesh is consigned to history and I really believe that day is coming.”